CVE-2026-57458

Vikunja is an open-source self-hosted task management platform. In version 2.3.0, a scoped API token limited to the oauth.authorize permission can call POST /api/v1/oauth/authorize, obtain an OAuth authorization code, and exchange the code at POST /api/v1/oauth/token for a normal bearer JSON Web Token (JWT) and refresh token. The resulting credentials are not restricted by the original API token's permissions, allowing access to routes outside its declared scope for the same user. Version 2.4.0 fixes the vulnerability.